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      https://www.ias.ac.in/article/fulltext/jess/128/08/0212

    • Keywords

       

      Kumaun Lesser Himalaya; Almora Crystalline Zone; North Almora Thrust Zone; Uranium enrichment; Spectrometry

    • Abstract

       

      Intensely deformed and mylonitised rocks of the Almora Crystalline Zone (ACZ) have shown the potential of $^{238}U$ and $^{232}Th$ enrichment. $^{232}Th$, $^{238}U$ and $^{40}K$ are investigated by gamma-ray spectrometry in the rock samples collected along the three selected traverses across the North Almora Thrust Zone (NATZ). Obtained average values of U and Th are much higher, 7.3 and 23.9 ppm, respectively, than the average upper crustal abundances (2.8 and 10.7 ppm). The Th/Ra(eU) varies between 2.1 and 23, indicating a higher concentration of Th. The enrichment is due to the remobilisation of the radioisotopes due to the intense mylonitisation and metamorphism from the granitic protolith. The zones of enrichment, although concentrated near NATZ, show a heterogeneous distribution.

    • Author Affiliations

       

      GAURAV JOSHI1 K K AGARWAL1 AMAR AGARWAL2 J R VIDAL-SOLANO3

      1. CAS in Geology, University of Lucknow, Lucknow 226 007, India.
      2. Institute of Earth and Environmental Sciences, Geology, University of Freiburg, Freiburg, Germany.
      3. Departamento de Geologıa, Universidad de Sonora, Hermosillo, Mexico.
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